| 摘要 |
PROBLEM TO BE SOLVED: To provide a chemically treated steel pipe having weather resistance and adhesion of a chemically treated film and having gloss and color change with time suppressed.SOLUTION: A chemically treated steel pipe has a chemically treated film on a plating layer on a steel plate. The plating layer is made of a zinc alloy containing 0.05-60 mass% of aluminum and 0.1-10.0 mass% of magnesium. The chemically treated film contains a fluorocarbon resin, a base resin, metal flakes, and a chemical treating component. The base resin is one or more kinds of resin selected from the group consisting of a polyurethane, polyester, acrylic resin, epoxy resin, and polyolefin. The content of the fluorocarbon resin is 3.0 mass% or more in terms of fluorine atom relative to the total amount of the fluorocarbon resin and the base resin, while the content of the base resin is 10 pts.mass or more relative to 100 pts.mass of the fluorocarbon resin. The content of the metal flakes is more than 20 mass% and 60 mass% or less in the chemically treated film.SELECTED DRAWING: Figure 1 |
