| 摘要 |
1363901 Zinc electro-plating SCHERING AG 9 Aug 1971[15 Aug 1970] 37366/71 Heading C7B A glossy, ductile Zn coating is electrodeposited e.g. on sheet steel from an acid Zn plating bath free from organic compounds which complex Zn ions, and which comprises a polycondensation product of formaldehyde with a naphthalene sulphonic acid. The bath may also contain a gloss-forming agent, preferably a polymeric compound with a carbonyl compound, e.g. polyethyl (or propyl)ene glycols, alkylaryl or fatty alcohol polyglycol ethers, fatty acid polyglycol esters, polyvinyl-pyrrolidones or amphoteric hydroxyethylation products, with benzoylacetonitrile, benzal- or benzoyl-acetone, acetophenone, 3-acetyl- or acetyl-pyridine or m-hydroxybenzaldehyde; thio compounds and wetting agents may be used. The electrolyte may comprise ZnCl 2 and NH 4 Cl, which may each be replaced by Zn sulphate, acetate or fluoroborate, and ammonium sulphate, sodium chloride or sulphate, and boric acid or aliphatic and/or aromatic carboxylic acids or salts thereof e.g. acetic, benzoic or salicyclic acid. |
