Alkaline zinc electroplating bath with or without cyanide content

Alkaline zinc electroplating aqueous bath containing a zinc salt, an alkali metal hydroxide, optionally other usual additives, and, if desired, an alkali metal cyanide and further one or more reaction products of an epihalohydrin with a nitrogen compound having at least 2 nitrogen atoms, characterized in that it contains as the epihalohydrin-reaction product a compound which has been obtained by reacting

• (a) the reaction product of a heterocyclic nitrogen compound containing at least two reactive nitrogen atoms which compound may be substituted with 1 or 2 methyl, ethyl or amino groups, with epihalohydrin in a molar ratio of 1:1 or of mixtures of such reaction products (in a molar of 1:1) with
• (b) ammonia, an aliphatic amine, polyamine and/or polyimine in a molar ratio of 1:0.3 to 1:1, said bath being further characterized in that it contains in addition the reaction product of a polyvalent alcohol or a mixture of polyvalent alcohols with epichlorohydrin or epibromohydrin in a molar ratio of 1:1, and further reacting the compound obtained with a heterocyclic compound having 1 or 2 nitrogen hetero-atoms which may be substituted by alkyl or alkoxy groups containing 1 to 3 carbon atoms, hydroxy or carboxy groups, or salts thereof in a molar ratio of 1:1.