ELECTRODEPOSITION BATHS CONTAINING CALCIUM SALTS

摘要

Disclosed are improved electrodeposition bath compositions comprising a resinous phase dispersed in an aqueous medium, the resinous phase being comprised of an active hydrogen containing ionic electrodepositable resin an d a curing agent, where the improvement comprises the addition to a lead-free electrodeposition bath of at least one calcium compound in an amount of abou t 10 to 10,000 parts per million of total calcium and not more than about 200 parts per million soluble calcium, based on electrodeposition bath weight. T he electrodeposition bath compositions are preferably cationic and provide for excellent corrosion resistance over a variety of metal substrates including untreated steel. Also disclosed is a method of electrocoating a conductive substrate using the improved electrodeposition bath compositions of the invention. Metallic substrates which are coated using the method of the invention are also disclosed.