Resin based post rinse for improved throwpower of electrodepositable coating compositions on pretreated metal substrates

摘要

Disclosed are methods for treating metal substrates, including ferrous substrates, such as cold rolled steel and electrogalvanized steel. The methods include (a) contacting the substrate with a pretreatment composition including a group IIIB or IVB metal and an electropositive metal, (b) contacting the substrate with a post rinse composition and (c) electrophoretically depositing an electrodepositable coating composition to the substrate, wherein the post rinse composition improves the throwpower of the subsequently applied electrodepositable coating composition. The present invention also relates to coated substrates produced thereby.