| 摘要 |
PURPOSE:To improve corrosion resistance, weatherability, chemical resistance and lubricity, to omit a degreasing process and to achieve the shortening of the process and the reduction of the cost by forming a chromate treatment layer on the plated surface of a galvanized steel plate and forming a high- molecular polyester film compounded with fine powder silica and a lubricating component thereon. CONSTITUTION:A chromate film is formed on the plated surface of a galvanized steel plate and baked at high temp. not only to enhance corrosion resistance but also to improve the adhesion of paint. The proper adhesion amount of Cr of the chromate film is 15-45mg/m<2> because corrosion resistance lowers in the case of 15mg/m<2> or less and a chromate color is imparted and the adhesion of paint lowers in the case of 45mg/m<2> or more. A high-molecular polyester org. film using melamine as a crosslinking agent is formed on the chromate layer. By this method, chemical resistance is enhanced and, by adding fine powder silica and wax, corrosion resistance and paint adhesiveness are improved and lubricity can be imparted. |
