George E. F. Brewer

Quantitative Prediction of Recycling Efficiency of Electrocoating Paint Solids Through Ultrafiltrate Rinse

Corrosion of automobile bodies became a severe problem in the 1950’s, due to the increased use of salt for the deicing of roads. The essentially flat outer surfaces of an automobile body were reasonably well protected against the corrosive action of salt and environment through a paint coat. The automotive bodies however corroded from the inside out. A paint application process was needed which would protect both inner and outer surfaces with a uniformly thin paint film.

Electrodeposition of Water-Dispersible Polymers

The interest in the formulation and manufacture of water-dispersible polymers has increased during the last ten years due to the awareness for environmental requirements. (See also the chapter by T. J. Miranda.) Much work has been done, aiming at reduced use — or elimination — of organic solvents as carriers of coating materials. One of the outstanding innovations in the exclusive use of water as carrier of coating materials is the electrocoating process (1).

Electrodeposition of Film-Forming Macroions

Abstract Ionizable film-forming macromolecules (RCOOH, RNH2, etc.) have recently found large-scale application as electrodepositable paints. Using bases or acids as solubilizers, macroanions (RCOO−) or macrocations (RNH3 are deposited from aqueous dispersions on the anode or cathode, respectively. The electric current deposits the paint solids practically free from volatile organics on the outer and inner surfaces of merchandise, resulting in higher corrosion protection at substantially lower cost. Bath droplets adhering to freshly electrocoated objects are rinsed back into the bath by a process involving ultrafiltration. Thus electrocoating is one of the ecologically and commercially most viable paint processes.