Solid mixture useful as a brightener for silver and gold electroplating comprises a dithiocarbamoyldithiocarbazate and a xanthate

摘要

Solid mixture comprising an alkali metal or ammonium dithiocarbamoyldithiocarbazate (I) and an alkali metal or ammonium xanthate (II) is new. Solid mixture comprising a dithiocarbamoyldithiocarbazate of formula (I) and a xanthate of formula (II) is new: M = alkali metal or ammonium; R = 1-12C hydrocarbyl. Independent claims are also included for the following: (1) an alkaline aqueous composition prepared by dissolving the above mixture in water in the presence of a base capable of adjusting the pH to 11-14; (2) a process for preparing the above mixture, comprising reacting thiosemicarbazide with excess (II) in a solvent at 35-100 deg C; (3) a bath for electrodeposition of silver, gold or their alloys, comprising the above mixture as a brightener.