摘要 |
Aqueous electroless nickel plating solutions comprising a water soluble nickel salt associated with a neutral zwitterion, e.g. alanine or glycine, and/or monovalent anion, e.g. lactate, nitrate, hypophosphite, acetate, sulfamate, hydrochloride, formate, propionate, trichloroacetate, trifluoroacetate, methanesulfonate, glycolate, aspartate or pyruvate, as counterion and chelant, a neutral, e.g. borate, or monovalent, e.g. hypophosphite, reducing agent, and a non-thiorea stabilizer, e.g. protonated dimethylamine or dimethylaminopropylamine or 2-hydroxyethanesulfonic acid. Valuable components of spent baths, e.g. nickel and neutral or monovalent anion species, can be advantageously recycled by employing solvent extraction and anion filtration operations. |