HIGH WORKABILITY PRECOATED STEEL SHEET EXCELLENT IN FLAWING RESISTANCE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To provide a precoated steel sheet high in flawing resistance and corrosion resistance and moreover excellent in workability and weatherability without using a vinyl chloride resin. ;SOLUTION: On a galvanized or aluminum plated steel sheet subjected to substrate treatment (zinc phosphate treatment, chromate treatment or the like), a primer-coating film of 10 to 80 μm thickness is formed from a baking cross- linked coating material contg. chromate rust preventive pigment of the amt. of 5 to 50 wt.% to the total content of nonvolatile contents in the coating material (for instance, an urea resin coating material contg. block isocyanate and polyamine, a melamine-cross-linked polyester coating material and an epoxy coating material), next, a top-coating material of 15 to 40 μm thickness is formed from a polyester or polyurethane coating material which may contain nylon or acrylic resin beads of 0.5 to 5 wt.% to the resin, and the total coating film thickness is controlled to 30 to 100 μm.;COPYRIGHT: (C)2000,JPO