GB1202827A - Improvements in or relating to nickel plating - Google Patents

Abstract

1,202,827. Electro-depositing nickel. M & T CHEMICALS Inc. March 24, 1969 [March 29, 1968], No.15373/69. Heading C7B. Semi-bright, S-free Ni is electro-plated onto a basis metal, e.g. steel, Cu, brass, bronze, Zn (particularly die castings bearing Cu plate), from an aqueous acidic Ni plating solution containing: at least one Ni compound providing Ni ions; one or more of (para) formaldehyde chloral (hydrate), bromal (hydrate); and a compound containing an oxyomegasulphohydrocarbon-di-yl coumarin anion, wherein the hydrocarbon-di-yl mority contains at least two carbon atoms, e.g. ethyl, propyl, butyl, pentyl, benzyl or (methyl) phenylene, and the oxyomegasulphohydrocarbon-di-yl group is substituted on the carboxyclic nucleus of the coumarin group; the cation of the latter compound may be H, Na, K, Li, Ni, Co or Mg, and other inert substituents on the carbocylic nucleus of the coumarin group may include H, halogen e.g. chloro, alkyl, alkaryl, aralkyl, aryl, alkoxy or aryloxy. Preferred examples of the latter compound are K or Na (6-chloro) 7-oxyomegasulphopropyl coumarin, diNa or Ni or Co 6, 7 or 7, 8-di (oxyomegasulpholpropyl) coumarin, Ni di (7, 7<1>-oxyomegasulphopropyl) coumarin, Na5- or K-7-oxyomegasulphobutyl coumarin, and Na 7-oxyomegasulphobenzyl coumarin. The plating bath may be of the following types: - Watts, sulphamate, fluoborate, chloride-free sulphate or sulphamate. The solution may also contain an anionic wetting agent e.g. Na lauryl sulphate or a Na dialkyl sulphosuccinate. Anodes may be of Pb or Ni. A relative velocity may be maintained between the bath and cathode, e.g. by ultrasonic vibration, rotation of the cathode, pumping electrolyte over the cathode or agitation of the electrolyte with propellers. Reference has been directed by the Comptroller to Specification 1, 135, 187.