Abstract: Additives for electrolyte baths for the electrodeposition of zinc or zinc alloy layer are described. The additives are polymers with terminal amino groups. These polymers are obtainable by reaction of at least one diamino compound (having two tertiary amino groups) with at least one di(pseudo)halogen compound, wherein the diamino compound is used in stoichiometric excess. The additives effect, in particular, a very little formation of bubbles and only few burnings as well as a uniform distribution of layer thickness in the electrodeposition of zinc or zinc alloy layers.

Abstract: The invention provides a process for depositing metallic layers from acidic or alkaline zinc or zinc alloy baths containing organic additives selected from brighteners, surfactants and complexing agents, a soluble zinc salt and optionally further metal salts selected from Fe, Ni, Co, Sn salts, wherein the bath can be purified continuously so that the process can be operated without interruption, as well as apparatus for carrying out this process.

Abstract: Additives for electrolyte baths for the electrodeposition of zinc or zinc alloy layer are described. The additives are polymers with terminal amino groups. These polymers are obtainable by reaction of at least one diamino compound (having two tertiary amino groups) with at least one di(pseudo)halogen compound, wherein the diamino compound is used in stoichiometric excess. The additives effect, in particular, a very little formation of bubbles and only few burnings as well as a uniform distribution of layer thickness in the electrodeposition of zinc or zinc alloy layers.

Abstract: The invention relates to an aqueous, alkaline cyanide-free electrolyte bath for de-positing zinc and zinc alloy coatings on substrate surfaces comprising (a) a source for zinc ions and optionally a source for further metal ions, (b) hydroxide ions, (c) a polymer of general formula I which is soluble in the bath and (d) at least one pyridinium compound of general formula II or III. The electrolyte bath is suitable for the galvanic deposition of bright and even zinc and zinc alloy coatings.

Abstract: The invention provides a process for depositing metallic layers from acidic or alkaline zinc or zinc alloy baths containing organic additives selected from brighteners, surfactants and complexing agents, a soluble zinc salt and optionally further metal salts selected from Fe, Ni, Co, Sn salts, wherein the bath can be purified continuously so that the process can be operated without interruption, as well as apparatus for carrying out this process.