A METHOD FOR ELECTROLYTIC GALVANISING USING ELECTROLYTES CONTAINING ALKANE SULPHONIC ACID

摘要

The invention relates to a method for electrolytically coating metalswith zinc or a zinc alloy. Matt surfaces are obtained by depositing zinc from an electrolyte solution containing a zinc salt selected from zinc sulphate or an alkane sulphate of zinc or mixtures thereof and optionally other metal salts, an acid selected from sulphuric acid or an alkane sulphonic acid or a mixture of both acids and at least one additive for improving surface roughness and for avoiding dendritic edge growth, selected from surface active compounds containing nitrogen which can be ionic or non-ionic, anionic surface active compounds containing nitrogen, and surface active compounds derived from multi-fuctional alcohols with at least three hydroxy groups. The invention also relates to an electrolytic composition for an electrolytically coating of metals with zinc or zinc alloys, in addition to the use of the above-mentioned additives for improving surface roughness and avoiding dentritic edge growth when metals are electrolytically coated with zinc or a zinc alloy in an electrolyte containing alkane sulphonic acid.