GB774614A - Improvements in or relating to the electrodeposition of nickel - Google Patents

Abstract

774,614. Electrodeposition of nickel. UDYLITE RESEARCH CORPORATION. April 5, 1955 [April 5, 1954], No. 9989/55. Class 41. Fine-grained nickel is deposited from an aqueous acid nickel bath containing a 5-, 6-, 7- or 8-monomethoxy- or 5-, 6-, 7- or 8-monoethoxy coumarin. Preferably the alkoxy group is attached in the 6-, 7- or 8-position and the addition agent is in a concentration of 0.05 to 2.0 gms/litre. For bright nickel the solution also contains either at least 0.05 gm/litre of an aryl sulphonyl compound such as a benzene sulphonic acid sulphonamide or sulphonimide, e.g. saccharin, with or without 0.001 to 0.4 gm/litre of quinoline, isoquinoline, their C-methyl or C- ethyl homologues or halogen ring-substituted derivatives thereof as in Specification 698,998, aryl and substituted aryl quaternary salts of these compounds as in Specification 736,556, or aliphatic quaternary salts of the compounds of Specification 698,998 or of pyridine and its analogous derivatives as in Specification 743,726; or 0.05 to 0.2 gm/litre of formaldehyde or 0.05 to 0.4 gm/litre of halogen substituted acetaldehydes, preferably of chloral or bromal hydrate with or without formaldehyde, with or without 0.1 to 1.0 gm/litre of trimethyl aconitate or di-(2-methoxyethyl) maleate. The baths are buffered with boric acid with or without formic, citric of fluoboric acids to pH 2 to 5.5 and typically contain either or both of nickel chloride and nickel sulphate. With nickel fluoborate baths, boric acid may be omitted from the buffer. Specifications 525;847 and 704,185 also are referred to.