BRIGHT-ZINC PLATING BATH

• Main Authors: GERD SENGE, ROLF SIEBURG
• Format: Patent
• Language: English
• Published: 27.06.1972
• Subjects: APPARATUS THEREFOR; CHEMISTRY; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; METALLURGY; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS

1321648 Electroplating with zinc RIEDEL & CO SPEZIALFABRIK FUR GALVANOTECHNIK 13 July 1970 [15 July 1969] 33960/70 Heading C7B A process for the production of an aqueous, alkaline, cyanide-free bright zinc-plating solution for the electrolytic deposition of high-lustre zinc coatings, comprising forming a first reaction product by mixing in water at about 20‹C. (a) at least one polyamine, (b) a salt wherein vanadium, niobium, tantalum, chromium, molybdenum or tungsten is present in the anion, and (c) at least one sulphur containing aliphatic, aromatic or heterocyclic compound which easily splits off sulphur and thereafter heating the first reaction product by the addition of hot water at about 70‹C. and subsequently adding thereto sodium hydroxide and formaldehyde to form a second reaction product and mixing the second reaction product with an aqueous, alkaline cyanide-free zinc plating electrolyte to produce the zinc-plating solution. The sulphur -containing compound(s) may be mercapto-thiazoline, mercapto-pyridine, thiourea or derivatives thereof, dithiocarbamic acid or its salts or derivatives thereof, or thioacetamide, thiocarbanilide, separately or in combination with one another. Specific solutions also include piperonal and vanillin. Specified electroplating conditions are a temperature of 10-30‹C., a current density of 0À5-4 A/dm2 and an exposure time of 10-20 mins.