Concentrate for activating and defining bath and bath obtained from this concentrate

Aqueous concentrate having a pH from 7 to 10 for preparing an activating and refining bath employed in processes of zinc phosphatization, based on an aqueous dispersion of Jernstedt salts, said concentrate containing

• from 2 to 20% by weight of said Jernstedt salts,
• from 0.2 to 8% by weight of at least one dispersing or sequestering agent selected from the group consisting of alkali and ammonium phosphonates of
• hydroxymethylphosphonic acid,
• hydroxypropylphosphonic acid,
• 1-hydroxyethylidene-1,1-diphosphonic acid,
• amino-tri(methylene-phosphonic) acid,
• ethylene-diamino-tetra(methylene-phosphonic) acid, and
• 2-phosphono-butane-1,2,4-tricarboxylic acid,
• from 0.05 to 7% by weight of at least one thickener based on a polysaccharide obtained by fermentation, under the action of a microorganism selected from the group consisting of the classes of Xanthomonas and Sclerotia, using a nutrient medium based on at least one constituent selected from the group consisting of glucose, sucrose, fructose, maltose, lactose and galactose, and a member selected from the group consisting of alkali nitrate and inorganic ammonium salt and mixtures thereof, the caseinate of sodium and the soluble extract of corn.