Abstract: An immersion bath composition and a method for applying a heavy, non-powdery coating of iron phosphate on a ferrous substance which is characterized by the addition of an effective amount of gluconic acid to a solution containing phosphoric acid, a soda ash, a chlorate or organic accelerator and water. Using conventional phosphating bath parameters, immersion of a ferrous substrate into the bath produces a heavy, strongly adherent, iron phosphate coating which is non-powdery or dust free and highly satisfactory for paint pre-treatment of the substrate surface.

Abstract: A final rinse for a phosphatized metal surface includes a phosphoric acid solution including aluminum chlorohydrate. The aluminum chlorohydrate solution is applied at a concentration of about 100 to about 1500 ppm at a pH of 3 to about 4.5. The pH is obtained by controlling the concentration of the phosphoric acid. This is preferably used to coat previously phosphatized metal surfaces such as iron, steel, aluminum and galvanize.

Abstract: By using an aqueous solution containing a phosphoric acids or phosphate salts together with carboxylic acids containing at least two carboxyl groups per molecule along with conventional mass finishing, a wide variety of metal parts may be simultaneously deburred, cleaned, and provided with a surface with good resistance to corrosion in humid air. The solution used preferably also contains non-ionic surfactant, corrosion inhibitor, and, for use in hard water areas, a water hardness stabilizer.

Abstract: During a method of phosphating a metal surface which includes at least in part iron or steel and is dipped into or flooded with a phosphating solution which contains layer-forming cations and nitrate or equivalent accelerators, the iron content is limited by a precipitation of iron phosphate. A partial volume of the phosphating solution is intermittently withdrawn from the bath tank and in a separate aerator is contacted with oxygen or an oxygen-containing gas. The iron phosphate sludge is removed from the resulting solution, which is then returned to the bath tank. The partial volume of the phosphating solution is supplied from below into and is aerated in an aerator, which is provided with an aspirating aerating agitator and which is tapered at least in its lower portion. When the aerator has been terminated, the phosphating solution which has been depleted of iron(II) is sucked off upwardly and is returned to the bath tank.

Abstract: A novel conversion coating composition and a method for treating corroded eel surfaces to convert them into a suitable substrate for accepting organic coatings are provided. Corroded steel surfaces treated with the novel composition of this invention by the improved method of application disclosed in this invention show wet adhesion and salt spray resistance properties markedly superior to those of surfaces which were treated with conventional, prior-art, commercially available compositions.

Abstract: The invention is a composition and method for treating aluminum. The composition comprises phosphonic acid, fluorozirconic acid, fluorotitanic acid, fluorohafnic acid, or fluorosilicic acid and a Mannich adduct of an polyalkenyl phenol or tannin. The aluminum is treated by contact with the composition. An inorganic-organic conversion coating is applied to the aluminum in a single step.

Abstract: A novel conversion coating composition and a method for treating corroded eel surfaces to convert them into a suitable substrate for accepting organic coatings are provided. Corroded steel surfaces treated with the novel composition of this invention by the improved method of application disclosed in this invention show wet adhesion and salt spray resistance properties markedly superior to those of surfaces which were treated with conventional, prior-art, commercially available compositions.

Abstract: Disclosed is a process of producing a phosphate coating on a metal having a surface which consists at least in part of iron or steel. The metal is contacted at a temperature in the range from 30.degree. to 50.degree. C. with a phosphatizing solution which contains 5 to 25 g/l zinc, 1 to 10 g/l manganese, 0.1 to 13 g/l iron(II), 5 to 40 g/l phosphate (calculated as P.sub.2 O.sub.5), 5 to 50 g/l nitrate, and which also contains 0.5 to 5 g/l fluoroborate (calculated as BF.sub.4), and 0.05 to 3 g/l tartaric acid and/or citric acid. The solution has been adjusted to weight ratios of Zn:P.sub.2 O.sub.5 =(0.5 to 3):1 and of Mn:Zn=(0.04 to 0.5):1 and to a ratio of free acid to total acid of (0.04 to 0.2):1.It is preferred to add nickel, copper and/or calcium to the phosphatizing solution and to adjust it to a content of Fe(II) not in excess of 10 g/l. The process is particularly suitable for preparing metals for cold working.

Abstract: Tetra-substituted zirconate or titanate organophosphate or organopyrophosphate coupling agents are combined with an alkali metal phosphate salt and a chlorite salt in an aqueous solution useful for copper oxidation. The concentration of the alkali metal phosphate salt in the aqueous solution must be 2.5 times higher than the titanate or zirconate coupling agent. A process for the preparation of superior compositions is also described wherein the coupling agent can not be mixed in an aqueous solution with the chlorite salt unless the alkali metal phosphate salt is present in the solution also.