Modified tin brightener for tin-zinc alloy electroplating bath

摘要

The brightener comprises an aqueous solution containing acetaldehyde and formaldehyde as primary brightener, an alcohol such as n-propyl alcohol, a surfactant and one component of a conventional two-part tin brightener as a secondary brightener. The modified brightener is suitable for use as a brightener in the deposition of tin-zinc alloys. The function of the other component of the tin brightener is accomplished by the formaldehyde and acetaldehyde. The problem of imbalance of the two components which can adversely affect brightening is thereby avoided. The tin brightener component may be a mixture of methanol, glycolated ethylene oxide, sulphuric acid, potassium acid tartrate, butyrophenone, zinc sulphate and hydroxylamine sulphate. The composition may also include allylacetoacetate as a preservative and additional stabilizing agents.