CATION ELECTRODEPOSITION COATING COMPOSITION HAVING EXCELLENT THIN FILM CORROSION RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a cation electrodeposition coating composition which is coated on various steel plates such as automotive steel plates to form the coating films having thin film thicknesses of <10μm and excellent hole-forming corrosion resistance. SOLUTION: This cation electrodeposition coating composition is characterized by comprising an amine-added epoxy resin containing an aromatic hydrocarbon-formaldehyde resin in an average amount of 5 to 25 wt. % as an epoxy-modifying agent, and a blocked polyisocyanate curing agent, having a chloride ion permeability of≤7.0×10-6g/cm-2/day (5% salt water, 50°C×24 hrs) in a film thickness of 10μm, and preferably further having a pigment component maximum particle diameter of≤1.5μm. COPYRIGHT: (C)2004,JPO&NCIPI