GB1169559A - Improvements in or relating to Electrolytic Nickel Plating - Google Patents

Abstract

1, 169, 559. Semi-bright nickel electro-plating. M. & T. CHEMICALS Inc. Oct.27, 1966 [Nov.1, 19651, No.48249/66. Heading C7B. Semi-bright nickel plate is electro-deposited from an aqueous acidic nickel plating bath including piperonal or piperonal substituted by a non- reactive group or groups and a water soluble acetylenic compound which acts as a levelling agent. The non-reactive substituent on the piperonal nucleus may be a saturated or unsaturated cyclic or acyclic hydrocarbon, ether, halogen, or ester group; while the acetylenic compound may include as substituents hydroxy, halogen, acetate, amide or acyloxy groups or alkoxy groups optionally substituted by one or more of hydroxy, halogen or carboxy or epoxy groups, such as butyne diol, 1-bromo-2-propyne, 1-methoxy -2-propyne, 1-formoxy-2-propyne, phenyl propiolamide, 1:2-di(#-hydroxyethoxy)-3-butyne, and 1-#-hydroxyethoxy-2-butyne-4-ol, 1:4-di(#- hydroxyethoxy)-2-butyne or the corresponding ammonium, sodium propylamine or like sulphated salts of such ethers. Preferably the electroplating bath, which may be a Watts, sulphamate, mixed Watts-sulphamate, fluoborate or chloridefree sulphate sulphamate or mixed sulphatesulphamate bath, contains per litre 0À01 to 1 g/1 of the piperonal compound and 0À01 to 0À2 g/1 of the acetylenic compound. The bath may also contain chloral hydrate, coumarin or derivatives such as an #-sulphohydrocarbyloxy coumarin semi-bright additive as in Specification 1,135,187, and surfactants such as sodium lauryl sulphate if mechanical bath agitation is used or sodium dialkyl sulphosuccinates if air agitation is employed. Soluble sulphur-containing nickel anodes may be used or with chloride-free baths insoluble lead anodes may be utilized, the nickel content being replenished by addition of nickel oxide, hydroxide or carbonate. With the use of agitation high speed plating at current densities of 120 amps/sq. dm. or more may be effected.