Water-based polyurethane coating composition

摘要

The present invention relates to a water-based coating composition suited for surface treatment of the metal sheets or plates to be used in building materials, household electric appliances, automobiles and so forth. The object of the present invention is to provide a water-based coating composition for the steel or metal coated steel surface treatment which gives coating films firmly adhering to metal plates and showing a high degree of hardening as well as excellent corrosion resistance, water resistance and weldability upon baking under low-temperature short-period conditions, has electric conductivity suited for electrodeposition coating and provides lubricating property in processing to thereby prevent powdering during processing as well as a method of forming coating films using said composition.