| 摘要 |
PROBLEM TO BE SOLVED: To prevent deposition and growth of marine organisms and to maintain good appearance and scenery for a long time by forming a color plastic film having a specified thickness and containing one or more kinds of zinc, zinc oxide and zinc compds. in a specified total volume ratio on the surface of a steel material. SOLUTION: A color plastic coating film 2 is formed on the surface of a steel piling sheet 1 having a component compsn. usually used. The color plastic coating film 2 contains one or more kinds of zinc, zinc oxide and zinc compds. which prevent deposition of marine organism such as shellfish and algae by 2 to 40 vol.% in total. If the volume ratio is <2%, the contamination prevention effect is not enough, and if it exceeds 40%, the adhesion strength with the steel poling sheet 1 degrades. The thickness of the color plastic coating film 2 is controlled to 2 to 4 mm in order to satisfy the long-term durability required for the steel poling sheet 1. The lower limit of 2 mm is determined so as to prevent damages of the film by soil and sand or drift wood, and the upper limit of 4 mm is determined from economical viewpoints. |
