Water-soluble organic cpds used as additives in electrolytic bath anolyte(s) - inhibit halogen gas formation during metal deposition, said cpds contg at least one double or triple bond and at least one hydrophilic group

摘要

Water-soluble organic cpds. contg. at least one double or triple bond and at least one hydrophillic group are used as additives to anolytes used in electrolytic coating baths. Pref. cpds. are vinylsulphonic acid, sodium vinylsulphonate, allylsulphonic acid, sodium allylsulphonate, vinylacetic acid, potassium vinylacetate, propynylsulphonic acid, sodium propynylsulphonate, diethylpropynyl ammonium chloride, dimethylpropynyl ammonium hydrogen sulphate, 1,4-butyndiol or sodium alpha-hydroxypropynyl sulphonic acid, used at concns. of 0.01-10 g/l in Zn, Ni or Cu electrolytic baths contg. an inert electrode encased in a membrane impervious to liquid, said membrane being composed of an ionic exchange material or a plastic. ADVANTAGE - Halogens arising from the galvanic deposition process are adsorbed and undergo chemical reaction, thereby avoiding formation of toxic gases. The claimed additives do not break down in acidic Ni, Cu or Zn electrolytes. Cheaper material not resistant to halogens may be used as anodes. Additives do not effect the deposited metals.