GB808104A - Electrodeposition of copper from aqueous alkaline cyanide solutions - Google Patents

Abstract

808,104. Electrodepositing bright cyanide copper. UDYLITE RESEARCH CORPORATION. Jan. 3, 1956 [Jan. 4, 1955], No. 229/56. Class 41. An aqueous alkaline copper cyanide electroplating bath contains 0.0002 to 0.006 g./l. of tellurium, preferably added as a telluride, tellurite, tellurate or telluric compound, e.g. as tellurium oxide dissolved in an alkali. The bath may also contain a wetting agent such as sodium lauryl sulphate or sodium decyl ether sulphate and/or a dispersing agent such as the sodium, potassium, or ammonium salt of a polymeric methylene naphthalene sulphonic acid produced by condensing formaldehyde with α- or #-naphthalene sulphonic acid, or of a nuclear sulphonated polystyrene. The bath may also contain 0.01 to 1 g./l. of arsenic, preferably added as sodium arsenite or arsenious acid. Typical cyanide baths to which the additions are made contain per litre 22.5 to 90 grams copper cyanide, 33.5 to 150 grams of alkali metal cyanide, 3.7 to 30 grams alkali metal hydroxide, and 30 to 160 grams alkali metal salt of an hydroxy organic acid, e.g. tartrate, glycolate, gluconate, citrate, malate, and may be used at temperatures up to 90‹ C.