| 摘要 |
PROBLEM TO BE SOLVED: To provide an insulating foamed polyolefin coated steel pipe that excels in heat retaining property, that greatly improves energy saving, and that also excels in heat insulating property as an economical liquid transporting pipe. SOLUTION: The insulating foamed polyolefin coated steel pipe is characterized in that an adhesive layer and a corrosion resisting layer are successively laminated on the outer face of a surface-treated steel pipe and that, on top of such surface, a foamed layer is laminated in which hollow particles suitable for high temperature, high pressure, and longtime extrusion coating are added to polyolefin resin. The hollow particles suitable for high temperature, high pressure, and longtime extrusion coating are characterized in that a high foaming rate is developed under melting-extrusion-shearing-foaming conditions of a foaming starting temperature of >170°C, a long foaming retention time of 1-60 min., and a screw tip end resin pressure of 0.1-50 MPa. COPYRIGHT: (C)2011,JPO&INPIT |
