COATING MATERIAL COMPOSITION CAPABLE OF FORMING LUBRICATING MEMBRANE EXCELLENT IN PRESS WORKABILITY AND WELDABILITY, AND LUBRICATING SURFACE TREATED STEEL SHEET USING THE SAME COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a coating material composition enabling a lubricating membrane excellent in press workability and weldability to be formed, and to provide a lubricating surface treated steel sheet using the same composition. SOLUTION: This coating material composition enabling a lubricating membrane excellent in press workability and weldability mainly comprises (A) aqueous composition of a polyurethane having carboxyl group in its molecule with a tertiary amine having a boiling point of >=120 deg.C as a neutralizer for the carboxyl group and (B) a lubricating function-imparting agent in an amount of 1-30 wt.% based on the solid content of the ingredient A. This lubricating surface treated steel sheet excellent in press workability and weldability features that chromate coatings are formed on both surfaces of a coated steel sheet in such a way that a chromium deposit has a quantity of 10-200 mg/m2/(one surface) in terms of metallic chromium and then the upper layers of both surfaces are or the upper layer of one surface is coated with the above coating material composition in such a way that the dried coating thickness is 0.1-2μm.