Photodegradation-resistant electrodepositable primer compositions

摘要

An electrodepositable primer composition having improved delamination resistance with regard to automotive topcoats is disclosed. The composition is particularly useful in conjunction with topcoats which transmit ultraviolet radiation. The composition includes an ionic resin and a hindered amine light stabilizer (HALS) which is preferably a hindered aminoether light stabilizer. A preferred hindered aminoether light stabilizer is bis-(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl)sebacate. The invention also includes a process for coating a substrate by applying the above-described primer composition and subsequently applying a topcoat. The process can alternatively include applying a standard primer composition to a substrate and subsequently applying a HALS compound to the electrodeposited substrate.