Abstract: The uniformity of gloss of a dried autodeposited resin film on a metal surface can be increased by rinsing the wet autodeposited film initially formed with an aqueous modifying rinse having a pH from 6 to 11 and comprising from 0.2 to 10.0 g/L in total of polymers of carboxylic acid monomers having an ethylenic double bond and salts thereof.

Abstract: A water-borne autodepositing coating composition that has a pH of 1.6 to 5 and contains as essential components a water-dispersible or water-soluble organic coating-forming resin, a liquid dispersion of carbon black, acid, and oxidizing agent, and that may contain metal ions as an optional component, has an excellent storage stability and produces a strongly adherent and highly corrosion-resistant coating when the liquid dispersion of carbon black is an aqueous dispersion in which carbon black is dispersed using as a dispersant a naphthalenesulfonate-formaldehyde condensate.

Abstract: A chromating treatment composition particularly suitable for preparing aluminum and stainless steel for clear coating comprises water, anions containing hexavalent chromium, trivalent chromium cations, phosphate ions, dry process finely divided silica, and acrylic and/or methacrylic acid polymer or copolymer in such amounts that:(A) the concentration of the total of hexavalent and trivalent chromium atoms is in the range from 1 to 60 g/L;(B) the (trivalent chromium atom)/(hexavalent chromium atom) weight ratio is in the range from 0.6 to 2.5;(C) the (phosphate ion)/(total chromium atoms in hexavalent chromium ions and trivalent chromium ions) weight ratio is in the range from 0.5 to 4.5;(D) the (dry process silica)/(total chromium atoms in hexavalent chromium ions and trivalent chromium ions) weight ratio is in the range from 0.1 to 5.

Abstract: A colorless chromate coating film is formed on a bright aluminum wheel by subjecting the surface of an aluminum wheel to a cathodic electrolytic treatment in an acidic aqueous solution containing not less than 2 g/l of hexavalent chromium ions, 20 to 2,000 ppm of sulfate ions, 10 to 400 ppm of fluorine (F) as fluoride and not less than 20 ppm of zirconium ions at a pH of 0.6 to 1.7 at a current density of 0.5 to 15 A/dm.sup.2 for at least 30 seconds, thereby forming a coating film with a chromium coating amount of 50 to 250 mg/m.sup.2.