ZINC ALLOY-PLATED CORROSION PREVENTIVE STEEL SHEET HAVING AN ORGANIC COATING LAYER THERON AND A METHOD FOR MAKING THE SAME

摘要

A corrosion preventive steel sheet having an organic coating layer is described. The steel sheet is comprised of a zinc alloy-plated steel sheet, and a chromate layer and an organic coating layer formed in this order on at least one side of the steel sheet. The organic coating layer is formed from a coating composition comprised of 100 parts by weight of a water-soluble urethane resin and from 5 to 80 parts by weight of colloidal silica. A method for making the corrosion preventive steel sheet is also described.