Alkaline spelter and spelter alloy electroplate bath and process

摘要

PROBLEM TO BE SOLVED: To obtain a uniformly plated glossy coating without pitching by using a water-soluble alkali plating bath contg. a zinc ion source and a polymer having a specified compsn, in the case of electrodeposition of zinc and zinc alloy on an electric conductive substrate. ;SOLUTION: A polymer used as an additive has a structure expressed by formula I, wherein Y is selected between S and O, and (n) is at least 1. R₁, R₂, R₃ and R₄ are same or different and selected from the group consisting of methyl, ethyl, isopropyl, 2-hydroxyethyl and CH₂CH₂(OCCH₂)_x OH (X is 0-6); R₅ is selected from the group consisting of (CH₂)-O-(CH₂)₂, (CH₂)-O-(CH₂)₂- O-(CH₂)₂ and CH₂-CHOH-CH₂-CHOH-CH₂. A plating bath preferably contains about 5-25 g of zinc, about 75-200 g of sodium hydroxide, about 1-1.5 g of the additive and required alloy elements per 1 liter of the bath.;COPYRIGHT: (C)1996,JPO