Abstract: The present invention provides an ammonia-free acid zinc plating bath for electrodepositing bright zinc on a substrate in which the zinc deposit produced thereby is ductile and presents a glossy to bright coating on the substrate over a wide cathodic current density range. The ammonia-free acid zinc plating baths of the invention comprise zinc ions, chloride ions, at least one polyoxyalkylated naphthol, at least one aromatic carboxylic acid or bath-soluble salt thereof, and at least one anionic aromatic sulfonic acid or bath-soluble salt thereof. In addition to the above components, the ammonia-free acid zinc plating baths of the invention may contain at least one nonionic polyoxyethylene compound and at least one aromatic aldehyde, ketone, or mixtures thereof. The ammonia-free acid zinc plating baths of the invention are free from significant amounts of complexing agents that would impede the removal of zinc ions from the baths prior to disposal.

Abstract: An acid plating bath and an improved process for electrodepositing level copper coatings are described. The improved copper plating baths and method include a bath soluble organic leveling compound which is obtained by reacting one or more epihalohydrins with one or more nitrogen-containing compounds which may be substituted pyridines, quinolines, isoquinoline or benzimidazole. Particularly improved results are obtained if the acid copper bath also contains, in addition to the leveling agent, a bath-soluble brightening agent and a wetting agent. The presence of the above-described leveling agent in acid copper plating baths produces a lustrous, smooth and level deposit of copper over a wide range of current densities.