Water-based coating composition for galvanized steel sheet or zinc alloy plated steel sheet and coated steel sheet

摘要

PPROBLEM TO BE SOLVED: To provide a water-based coating composition giving a coating film having excellent corrosion resistance and processability without using a chromate-based rust prevention pigment and especially suitable for producing a precoated metal and provide a steel plate coated with the water-based coating composition. PSOLUTION: The water-based coating composition for galvanized steel plate or zinc alloy plated steel plate contains a water-based organic resin component, a calcium condensed phosphate, aluminum tripolyphosphate, an oxyacid salt of a metal (excluding chromium), and phosphoric acid or a water-soluble phosphoric acid salt as essential components. The coated steel plate has a coating film formed by applying the water-based coating composition to a galvanized steel plate or a zinc alloy plated steel plate. PCOPYRIGHT: (C)2006,JPO&NCIPI